Concrete pavement



(No Model.)

.P. M .BRUNER. CONCRETE PAVEMENT.

Patented Apr. '7, 1891.

me mums Pnens co., mom-mac wuumwmu, u. c.

have invented a certain. new and useful Imscription, reference being had to the accom- N ITE TATES' PRESTON M. BRUNER, OF ST. LOUIS, MISSOURI.

.CONCRETE SEECIFICATION forming part of Letters PAVEMENT.

Patent No. 150,054, dated April-'7, 1891.

Application filed May 21,1889. Serial No. 311,589. (No specimens.)

To all whom it may concern:

Beit known that I, PRESTON M. BRUNER, of the city of St. Louis, in the State of Missouri,.

provement in Concrete Pavements, of which the following is a full, clear, and exact depanying drawings, forming part of this specification, and in which Figure I is a plan view illustrative of my invention. Fig. II is a detail transverse section of two of the blocks. Figs. III and VI are diagrams made for the purpose of illustrating between my invention and what is old. Fig. IV is a section similar to Fig. II, but showing the joint complete. Fig. V is a transverse section through a tool or instrument for forming the joints between the blocks. Fig. VII is a View of a tool ineommon use for beveling the blocks at the joints. Fig. VIII is a vertical sectional View of a modification.

My present invention relates to that class of concrete pavements in which the material is put in place in a plastic or soft condition; and my invention consists in an improved pavement of this kind, the joint being of such a character as to permit the blocks to move under expansion and contraction, due to different temperatures, and which will avoid the chipping or breaking of the blocks along the upper edges, all of which will be more fully described hereinafter.

Referring to the drawings, 1 2 represent adjacent blocks of a pavement. represents the scantling or strips used in forming the blocks for the purpose of keeping them rectangular or to preserve their symmetry. The old method of making such pavements is to placetwo of these strips 3 the distance apart to make the desired size of blockthat is, one of the strips would be placed as shown at A, Fig. 1, and the other atB. After the block 1 is made the strip at B is removed to C, and the block 2 is then made. It will be understood that the cement sets very rapidly, so that after block 1 is formed and before block 2 is formed, block 1 has become sufficiently hardened so that block 2 will not become united or joined to it, although the material of block 2 is placed up against block 1, which forms one of its walls, the strip 3 at forming the other wall.

It has been customary to form the lower portion or body of the blocks of coarser ma terial than the upper surface. This is illustrated in Figs. Ill and VI. It has also been customary to run a trowel along the joint between the two blocks after they have become suificiently set, but before they are so hard as to prevent the passage of the trowel. This leaves a ragged space or joint between the upper portions of the two blocks, as shown at 5, Fig. III, which leaves the upper edges of the blocks, as shown at 6, Fig. III, acute or sharp, so that they are liable to become chipped or broken off, which results in defacing the pavement. The object of passing the trowel between the blocks is to form a straight joint or line to well define the individuality of the blocks, and also serves the purpose of allowing the blocks to expand in cold Weather without breakage. To make clean and ornamental edges of the sharp edges at 6, as stated, it has been customary to run a V-shaped instrument (such as is shown in Fig. VII) through the groove 5 at its upper end. This bevels off the edges of the blocks, as shown at S, Fig. VI, but at the same time it forces a portion of the material into the groove 5 and closes it, as shown at 7, Fig. VI, and thus subjects the pavement to possible defacement at joint and defeats the possibility of the expansion of the blocks without breakage, as it will not permit them to move toward each other, but causes them to upheave.

Now the object of my invention is toform a real separate joint, instead of the old separable joints, by means of the slots 5 and bevels 8 without any disadvantageresultingtherefrom. To this end I use a tool such as is shown in Fig. V. jecting downward from a head 10, and at the point of connection between the tongue and head the tool is formed with an enlargement, as shown at 11. The tongue 9 forms the grooves 5 between the blocks, the parts 11 true the upper end of the grooves,and the head limits the downward movement of the tool, so that by pressing it firmly upon the blocks as it is drawn from end to end of the blocks, a-

slot or groove of uniform depth is formed and the bevels or blunt corners S of uniform inclination are also formed. In this manner I am able to construct or make apavement hav- Itis provided with a tongue 9 pro- 2 esopee i'ng many advantages and none of the disadgaqtages heretofore existing, as above speci- In the old method of making the grooves by means of a trowel their walls were ragged, as shown at Fig. Ill, and it very frequently happened that the trowel would be passed along to one side or the other of the natural joint, (or to one side or the other of the vertical wall of block 1,) which when frosts came would cause two seams, one where the oldfashioned tool, Fig. VII, had been passed and the other directly over the natural joint, and the frost causing always a breakage at the true and natural joint. To avoid these ragged walls and misplacing of the joints by the tool I round or blunt the coarser or body parts of the blocks, as shown at 12, Figs. II and IV, and fill in the spaces between these blunt or .rounded edges 12 with the finer top covering or coating, so that when the tool shown in Fig. V is introduced it is bound to seat directly over the natural joint, (there being less resistance in the finer than in the coarser material,) and the groove being made in the fine material, smooth instead of ragged walls are formed, and the jointis atrue open joint separate and not separable.

I have shown the grooves formed by the tool extending not quite to the bottom of the blocks; but their depths may be varied, or they may extend entirely through or clear to the bottom of the blocks, as shown in Fig. VIII,and when not extending entirely through the part remaining will take any-thrust between the blocks, and yet when any block is lifted the narrow rim easily breaks off under the transverse strain.

I claim as my invention 7 1. An artificial stone pavement having open clear-cut grooves formed through the main body thereof and the upper edges of said grooves being beveled, and the material of the pavement composing the walls of said grooves and said bevels being worked or compacted to a greater density than the body of the pavement, substantially as set forth.

2. An improved pavement of the kind described, having a body portion or lower stratum formed with blunt edges at 12 and a coating or upper stratum having portions extending down between the blunt edges 12, said upper stratum having a groove extending through it, but not through thelower stratum, substantially as set forth.

8. An improved pavement of the kind described, having a coarser body portion beveled or rounded at 12 and a finer coating that extends down below the upper surface of the body portions and which is grooved, substantially as and for the purpose set forth.

4. An improved pavement of the kind described, having a body portion or lower strat um of coarse material,formed with blunt edges at 12, and an upper stratum or coating 1 of finer material projecting down between said blunt portions, said coating being grooved between said blunt portions, and said groove having beveled edges, substantially as set forth.

PRESTON M. BRUNER.

In presence of GEO. H. KNIGHT, EDW. S. KNIGHT. 

